1,295 research outputs found
The impact of the economic integration in the European Union on initial public offering activity
Mestrado em FinançasOs impactos da integração económica, bem como as atividades envolventes às Ofertas Públicas Inicias (OPI), têm sido extensamente estudadas, no entanto, a relação entre estes dois tópicos, isto é, o Impacto da Integração Económica nas Ofertas Públicas Iniciais, carece de pesquisa. Esta tese procura analisar esta relação na União Europeia (UE) usando por base as teorias de Integração económica e atividade OPI, bem como o processo histórico de integração na UE. A teoria aponta para um efeito positivo da integração económica na atividade OPI. Este estudo estabelece a hipótese de que a Integração económica na UE, identificada como (1) um país juntar-se à UE, (2) um país adotar o Euro como moeda oficial, (3) um país juntar-se à área Schengen levam a um aumento significativo nas atividades de OPI nesse país. Esta análise baseia-se em dados de painel compostos pelos 28 estados membros, num período compreendido entre 1 de janeiro de 1989 e 31 de dezembro de 2018. O resultado de 10 Mixed Linear Models, sugere que a integração económica, na forma de integrar a EU, tem um impacto positivo nas atividades de OPI. As hipóteses de que adotar a moeda única e aderir à área Schengen têm um impacto positivo, não foram suportadas pelos resultados.The Impact of Economic Integration has been studied on a number of topics. Extensive research was also conducted on Initial Public Offering (IPO) activity. The relationship between these topics, i.e. the Impact of Economic Integration on Initial Public Offering activity, has not yet been subject to research. This dissertation studies this relationship in respect to Economic Integration in the European Union (EU). It is based on the theories of Economic Integration and IPO activity, as well as on the historical integration process in the EU. Theory leads to the assumption of a positive impact of Economic Integration on IPO activity. This study hypothesizes that Economic Integration in the European Union, identified by (1) a country joining the European Union, (2) a country adopting the Euro as its currency, (3) a country joining the Schengen-Area, leads to a significant increase in IPO activity in that country. The analysis is based on a panel data set for all 28 EU member states, from January 1st, 1989 to December 31st, 2018. Results of ten Mixed Linear Models suggest that Economic Integration in the EU, in form of joining the Union, has a positive impact on IPO activity. The impact of adopting the Common Currency and joining the Schengen-Area was not supported by the results.info:eu-repo/semantics/publishedVersio
Determination of the origin and magnitude of logarithmic finite-size effects on interfacial tension: Role of interfacial fluctuations and domain breathing
The ensemble-switch method for computing wall excess free energies of
condensed matter is extended to estimate the interface free energies between
coexisting phases very accurately. By this method, system geometries with
linear dimensions parallel and perpendicular to the interface with
various boundary conditions in the canonical or grandcanonical ensemble can be
studied. Using two- and three-dimensional Ising models, the nature of the
occurring logarithmic finite size corrections is studied. It is found crucial
to include interfacial fluctuations due to "domain breathing".Comment: 5 pages, 4 figure
The Non-Innocent Role of Hole-Transporting Materials in Perovskite Solar Cells
The race to the future generation of low-cost photovoltaic devices continuouslytakes on added momentum with the appearance of novel practical solutions forthe fabrication of perovskite solar cells (PSCs), a paradigm technology forultracheap light-to-electricity conversion. Much has been done in the past fewyears toward defining standard protocols for the assessment of their efficiencyand stability, aiming at achieving a worldwide consensus on the issue, that willallow reliable reporting of new data. While this is undoubtedly a step aheadtoward commercialization of these devices, it also often triggers researchers totest record architectures using benchmark configurations, mainly for whatregards the ancillary layers that extract electrical charges from the photoexcitedperovskite. In particular, the mostly used hole-transporting material (HTM) is thesmall-molecule spiro-OMeTAD, which is also well known to be the origin of PSCdegradation after prolonged operation. Herein, it is aimed to remark the hugeimpact of the HTM on PSC performance, recalling major issues associated withthe conventional spiro-based one and providing an overview of state-of-the-artalternatives. Finally, possible scenarios for the future development of smartHTMs are also envisioned, as charge-extracting layers, with a real active role inensuring PSC operational stability
Prediction of adiabatic blanking process properties with temperature dependent fracture criterion
Radionuclide, magnetic resonance and computed tomography imaging in European round back slugs (Arionidae) and leopard slugs (Limacidae)
Other than in animal models of human disease, little functional imaging has been performed in most of the animal world. The aim of this study was to explore the functional anatomy of the European round back slug (Arionidae) and leopard slug (Limacidae) and to establish an imaging protocol for comparative species study. Radionuclide images with single photon emission computed tomography (SPECT) and positron emission tomography (PET) were obtained after injections of standard clinical radiopharmaceuticals (99m)technetium dicarboxypropane diphosphonate (bone scintigraphy), (99m)technetium mercaptoacetyltriglycine (kidney function), (99m)technetium diethylenetriaminepentaacetic acid (kidney function), (99m)technetium pertechnetate (mediated by the sodium-iodide symporter), (99m)technetium sestamibi (cardiac scintigraphy) or F-18-fluoro-deoxyglucose (glucose metabolism) in combination with magnetic resonance imaging (MRI) and computed tomography (CT) for uptake anatomic definition. Images were compared with anatomic drawings for the Arionidae species. Additionally, organ uptake data was determined for a description of slug functional anatomy in comparison to human tracer biodistribution patterns identifying the heart, the open circulatory anatomy, calcified shell remnant, renal structure (nephridium), liver (digestive gland) and intestine. The results show the detailed functional anatomy of Arionidae and Limacidae, and describe an in vivo whole-body imaging procedure for invertebrate species
Tuning the optical properties of 2D monolayer silver-bismuth bromide double perovskite by halide substitution
: Silver-bismuth double perovskites are promising replacement materials for lead-based ones in photovoltaic (PV) devices due to the lower toxicity and enhanced stability to environmental factors. In addition, they might even be more suitable for indoor PV, due to the size of their bandgap better matching white LEDs emission. Unfortunately, their optoelectronic performance does not reach that of the lead-based counterparts, because of the indirect nature of the band gap and the high exciton binding energy. One strategy to improve the electronic properties is the dimensional reduction from the 3D to the 2D perovskite structure, which features a direct band gap, as it has been reported for 2D monolayer derivates of Cs2AgBiBr6obtained by substituting Cs+cations with bulky alkylammonium cations. However, a similar dimensional reduction also brings to a band gap opening, limiting light absorption in the visible. In this work, we report on the achievement of a bathochromic shift in the absorption features of a butylammonium-based silver-bismuth bromide monolayer double perovskite through doping with iodide and study the optical properties and stability of the resulting thin films in environmental conditions. These species might constitute the starting point to design future sustainable materials to implement as active components in indoor photovoltaic devices used to power the IoT
Analyzing M-CSF dependent monocyte/macrophage differentiation: Expression modes and meta-modes derived from an independent component analysis
<p>Abstract</p> <p>Background</p> <p>The analysis of high-throughput gene expression data sets derived from microarray experiments still is a field of extensive investigation. Although new approaches and algorithms are published continuously, mostly conventional methods like hierarchical clustering algorithms or variance analysis tools are used. Here we take a closer look at independent component analysis (ICA) which is already discussed widely as a new analysis approach. However, deep exploration of its applicability and relevance to concrete biological problems is still missing. In this study, we investigate the relevance of ICA in gaining new insights into well characterized regulatory mechanisms of M-CSF dependent macrophage differentiation.</p> <p>Results</p> <p>Statistically independent gene expression modes (GEM) were extracted from observed gene expression signatures (GES) through ICA of different microarray experiments. From each GEM we deduced a group of genes, henceforth called <it>sub-mode</it>. These <it>sub-modes </it>were further analyzed with different database query and literature mining tools and then combined to form so called <it>meta-modes</it>. With them we performed a knowledge-based pathway analysis and reconstructed a well known signal cascade.</p> <p>Conclusion</p> <p>We show that ICA is an appropriate tool to uncover underlying biological mechanisms from microarray data. Most of the well known pathways of M-CSF dependent monocyte to macrophage differentiation can be identified by this unsupervised microarray data analysis. Moreover, recent research results like the involvement of proliferation associated cellular mechanisms during macrophage differentiation can be corroborated.</p
Controlled Size Reduction of Liquid Exfoliated Graphene Micro-Sheets via Tip Sonication
Liquid exfoliation of three-dimensional bulk solids with an inherent layered structure is an effective and scalable method to produce stable re-aggregation colloidal inks of 2D materials that are suitable for solution processing. Shear mixing is a relatively gentle technique that allows exfoliation while preserving the native lateral size of the 3D precursors, while tip sonication often leads to extensive structural damage, producing 2D sheets where many edge defects are introduced.
We present a mixed approach to obtain liquid dispersions of few-layer graphene flakes, wherein the average lateral size of the colloids can be tuned in a controlled way. This strategy relies on the application of defined tip sonication steps on graphene inks previously prepared through the use of a shear mixer, thus starting with already-exfoliated micro-sheets with a limited amount of edge defects. Our approach could represent a valuable method to prepare 2D material inks with variable
size distributions, as differences in this parameter could have a significant impact on the electronic behavior of the final material and thus on its field of application
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